Steam turbine system with impulse stage having plurality of nozzle groups

Abstract

A steam turbine system, including a plurality of blade stages arranged axially along a first shaft, an impulse stage configured upstream of the plurality of blade stages, the impulse stage having an impulse wheel and a casing, the casing including a plurality of inlet sections with each of the plurality of inlet sections having a corresponding nozzle group and operatively connected to a corresponding control valve controlling a first steam flow through the corresponding nozzle group, a first inlet configured to provide the first steam flow through the impulse stage and the plurality of blade stages, and, a second inlet configured to provide a second steam flow to the plurality of blade stages and bypassing the impulse stage.

What is claimed is: 
     
         1 . A steam turbine system, comprising:
 a plurality of blade stages arranged axially along a first shaft;   an impulse stage configured upstream of the plurality of blade stages, the impulse stage having an impulse wheel and a casing, the casing including a plurality of inlet sections with each of the plurality of inlet sections having a corresponding nozzle group and operatively connected to a corresponding control valve controlling a first steam flow through the corresponding nozzle group;   a first inlet configured to provide the first stream flow through the impulse stage and the plurality of blade stages; and,   a second inlet configured to provide a second steam flow to the plurality of blade stages and bypassing the impulse stage.   
     
     
         2 . The system of  claim 1 , wherein at least one of the plurality of nozzle groups has a different number of nozzles than the remaining nozzle groups. 
     
     
         3 . The system of  claim 1 , wherein each of the nozzle groups of the impulse stage are configured to direct e first steam flow to bypass at least one of the plurality of blade stages. 
     
     
         4 . The system of  claim 1 , further comprising a first housing enclosing the plurality of blade stages and the impulse stage. 
     
     
         5 . The system of  claim 1 , further comprising a first housing enclosing the plurality of blade stages, and a second housing enclosing the impulse stage arranged on the first shaft. 
     
     
         6 . The system of  claim 1 , further comprising a first housing enclosing the plurality of blade stages, and a second housing enclosing the impulse stage arranged on a second shaft. 
     
     
         7 . A power plant, comprising:
 a steam source for generating a steam flow;   a high pressure turbine system having:
 a plurality of blade stages arranged axially along a first shaft; 
 an impulse stage configured upstream of the plurality of blade stages, the impulse stage having an impulse wheel and a casing, the casing including a plurality of inlet sections with each of the plurality of inlet sections having a corresponding nozzle group and operatively connected to a corresponding control valve controlling a first steam flow through the corresponding nozzle group; 
 a first inlet configured to provide the first steam flow through the impulse stage and the plurality of blade stages; and, 
 a second inlet configured to provide a second steam flow to the plurality of blade stages and bypassing the impulse stage; 
   an intermediate pressure turbine system and a low pressure turbine system fluidly coupled to the high pressure turbine system; and,   a first generator driven by the first shaft.   
     
     
         8 . The power plant of  claim 7 , wherein at least one of the plurality of nozzle groups of the casing has a different number of nozzles than the remaining nozzle groups. 
     
     
         9 . The power plant of  claim 7 , wherein each of the corresponding nozzle groups of the impulse stage are configured to direct the first steam flow to bypass at least one of the plurality of blade stages. 
     
     
         10 . The power plant of  claim 7 , further comprising a first housing enclosing the plurality of blade stages and the impulse stage of the high pressure steam turbine system. 
     
     
         11 . The power plant of  claim 7 , further comprising a first housing enclosing the plurality of blade stages, and a second housing enclosing the impulse stage arranged along the first shaft. 
     
     
         12 . The power plant of  claim 7 , further comprising a first housing enclosing the plurality of blade stages, and a second housing enclosing the impulse stage arranged along a second shaft driving a second generator. 
     
     
         13 . An impulse stage system for a steam turbine system, the impulse stage system comprising:
 an impulse wheel arranged on a first shaft; and,   a casing including a plurality of inlet sections, wherein each of the plurality of inlet sections have a corresponding nozzle group and operatively connected to a corresponding control valve controlling a first steam flow through the corresponding nozzle group   a first inlet configured to feed the first steam flow through the impulse stage.   
     
     
         14 . The system of  claim 13 , wherein at least one of the corresponding nozzle groups has a different number of nozzles than the remaining nozzle groups.